17-31226465-C-G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_ModerateBP6BS2_Supporting

The NM_001042492.3(NF1):​c.2032C>G​(p.Pro678Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000118 in 1,613,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P678L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense

Scores

1
4
14

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:2

Conservation

PhyloP100: 5.72

Publications

7 publications found
Variant links:
Genes affected
NF1 (HGNC:7765): (neurofibromin 1) This gene product appears to function as a negative regulator of the ras signal transduction pathway. Mutations in this gene have been linked to neurofibromatosis type 1, juvenile myelomonocytic leukemia and Watson syndrome. The mRNA for this gene is subject to RNA editing (CGA>UGA->Arg1306Term) resulting in premature translation termination. Alternatively spliced transcript variants encoding different isoforms have also been described for this gene. [provided by RefSeq, Jul 2008]
NF1 Gene-Disease associations (from GenCC):
  • neurofibromatosis type 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Genomics England PanelApp
  • neurofibromatosis-Noonan syndrome
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
  • Moyamoya disease
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • hereditary pheochromocytoma-paraganglioma
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial ovarian cancer
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.15408427).
BP6
Variant 17-31226465-C-G is Benign according to our data. Variant chr17-31226465-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 231733.
BS2
High AC in GnomAd4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NF1NM_001042492.3 linkc.2032C>G p.Pro678Ala missense_variant Exon 18 of 58 ENST00000358273.9 NP_001035957.1 P21359-1
NF1NM_000267.4 linkc.2032C>G p.Pro678Ala missense_variant Exon 18 of 57 NP_000258.1 P21359-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NF1ENST00000358273.9 linkc.2032C>G p.Pro678Ala missense_variant Exon 18 of 58 1 NM_001042492.3 ENSP00000351015.4 P21359-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152076
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250606
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461532
Hom.:
0
Cov.:
34
AF XY:
0.0000124
AC XY:
9
AN XY:
727078
show subpopulations
African (AFR)
AF:
0.000120
AC:
4
AN:
33460
American (AMR)
AF:
0.0000895
AC:
4
AN:
44682
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111778
Other (OTH)
AF:
0.00
AC:
0
AN:
60368
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.521
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152076
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74282
show subpopulations
African (AFR)
AF:
0.000121
AC:
5
AN:
41396
American (AMR)
AF:
0.00
AC:
0
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.535
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2Benign:1
Mar 15, 2022
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 28, 2023
St. Jude Molecular Pathology, St. Jude Children's Research Hospital
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The NF1 c.2032C>G (p.Pro678Ala) change has a maximum subpopulation frequency of 0.020% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with Neurofibromatosis type 1. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

Feb 04, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:2
Oct 21, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

May 07, 2015
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.P678A variant (also known as c.2032C>G), located in coding exon 18 of the NF1 gene, results from a C to G substitution at nucleotide position 2032. The proline at codon 678 is replaced by alanine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of p.P678A remains unclear. -

not specified Uncertain:1
May 05, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: NF1 c.2032C>G (p.Pro678Ala) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 250606 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.2032C>G in individuals affected with Neurofibromatosis Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. Two ClinVar submitters have assessed the variant since 2014: both classified the variant as of uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1
Apr 20, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 25486365) -

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Benign:1
Dec 09, 2022
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.081
BayesDel_addAF
Benign
-0.26
T
BayesDel_noAF
Benign
-0.43
CADD
Benign
19
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.48
T;.;T
Eigen
Benign
-0.18
Eigen_PC
Benign
0.015
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.90
D;D;D
M_CAP
Benign
0.040
D
MetaRNN
Benign
0.15
T;T;T
MetaSVM
Benign
-0.94
T
MutationAssessor
Benign
0.95
L;L;.
PhyloP100
5.7
PrimateAI
Uncertain
0.70
T
PROVEAN
Benign
-1.1
N;N;N
REVEL
Benign
0.12
Sift
Benign
0.035
D;D;D
Sift4G
Benign
0.14
T;T;T
Polyphen
0.0
B;B;.
Vest4
0.46
MutPred
0.24
Gain of helix (P = 0.0078);Gain of helix (P = 0.0078);.;
MVP
0.38
MPC
0.67
ClinPred
0.30
T
GERP RS
4.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.099
gMVP
0.41
Mutation Taster
=84/16
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs758691069; hg19: chr17-29553483; API